Nigel Planer plays Laurence Didcott, new French teacher at London's Mansion House public school. Although undoubtedly and unfalteringly well-intentioned, he is actually rather feckless, and somewhat of a one-man disaster area. His constant unquestioning drive for change and improvement only serves to alienate him somewhat from the other teachers, who have long been resigned to a repetitive daily existence of educational mediocrity!